Nerve growth factor (NGF) is a target-derived factor and interacts with its receptor, TrkA, on the axon tip, to exert its effects on neuronal differentiation and survival. To date, little is known on how NGF signalling in axons is communicated to the cell body. Recent evidence suggests that neurons exploit small vesicles that contain activated NGF/TrkA complexes, to convey the NGF signal from the distant axon to the nucleus, where changes in geneexpression are induced. Aim of the project is to examine occurrence and identity of proteins thatare associated with activated NGF/TrkA in these endosomes. To this end, protein maps will be generated of vesicles from NGF-treated versus control cells, using 2-D gel electrophoresis, and mass spectrometry will be used to identify differential gel spots.